The inter-locking network model of city relations (Taylor 2001, 2004) was calibrated in two previous projects for 2000 (Project 10) and 2004 (Project 19). In this project we continue the calibration to 2008. In the first two exercises a large service values matrix was created: 100 ;global service firms x 315 cities for 2000, and 80 firms x 315 for 2004. The same firms and cities were studied to provide 2000-04 change data (Taylor and Aranya 2006). The reason for the drop of 20 firms to just 80 in 2004 is largely due to the disappearance of firms (take-overs, etc). Such a data collection could not continue with this level of erosion of firms. Thus the new data collection is based upon a revised methodology. In a addition we take the opportunity to extend the data and analyses to city market size for services.

Cities

The 315 cities from the earlier projects were derived from knowledge of the world market in advanced producer services. Building on this roster we add further cities from areas previously under-represented through new knowledge plus use of the following 3 rules: include (i) all cities with populations over 1.5 million; (ii) all capital cities of states of over one million inhabitants; (iii) all cities that house the headquarters of a Forbes 2000 company (see firms below). The result is a new roster of over 500 cities.

Firms

In the two previous research projects firms were not chosen in a systematic pattern except to define them as ‘global' in their office span (Taylor et al 2002). Here we take a different approach and choose the leading firms in their respective sectors. The original sectors are to be included plus additional sectors. In addition world cities are interpreted in two ways: as nodes in networks (as per the other projects) and as business centres. The latter is new to this project : we now measure two processes (i) world city network formation through firms that do business through networks of offices (advanced producer services) and (i) world city market formation through firms that create the city markets for the services (e.g. firm headquarters). These can be termed service centres and decision centres respectively (Rossi, Beaverstock and Taylor (2007).

The information collected on these firms do not inform network processes, rather the spaces of flows are through hierarchies (management), chains (hotels), sequences/rounds (exhibitions, fairs), and scatters (science parks). Thus the data collection will be frequencies of occurrence per city.